Improvement in steam-regulators for paper-driers



DANIEL CROSBY, or HAMPDENMA1NE.

` www 'Letters Patentino. 112,422, dated March 7, 1871.

i `IMPROVEMENT IN STEAM-REGULATORS FOR PAPER-DRIERS.

The Schedule referred to in these Letters atent and making peut of thesame.

I, DANIEL GROsBY, offHam pden, Penobscot county, Maine, have invented anImproved Steam-Regulator Y for Paper-machine Driers, and for otherpurposes, of

which the following is a'specification.

Figures 1,2, and 3 are sectional elevations of di'erent varieties of myinvention.

. This invention has `for its object, generally, to obtain from a boilerthe amountof steam, within which varies from time to time, a constantamount of steam within a vessel communicating with the boiler; andparticularly to obtain from a boiler a constant amount of steam withinthe driers of a paper-machine, to the end that paper may be drieduniformly.

VThe 'invention consists in a:safety-valve, so arranged with referencetothe pipe by ywhich steam is conducted from the boiler to the driers asto regulate by its movementsthe admission of steam to the latter,allowing only enough to pass to maintain a constant quantity within thedriers. y Referring to the drawinga are the driers of a-paper-machine,or the large hollow cylinders, around the perimeter-s 'of whichthe paperpasses in a moist state,and which require to be kept filled with steam`in order tofurnish theheat y necessary for drying `the paper during itspassage.

,b is the pipe by which steam is admitted to the driers.- y i Y In orderto securewithin the driers a constant supply of steam, either of twomechanisms may heemployed,' which, though differing to some extent inconstruction, are alike in" prnciple one of which mechanisms is showninfigs. l 'and4 2, and the other in hg. 3, both of them agreeing inthis, that the steam from the boiler, `before entering the driers, hasAto pass a safety-valve, by the-movements of which therequisite constancyof supply is obtained. i

In figs.- l and 2, A is the\pipe by which steam is l `taken from theboiler, and in which the quantity of' l steam'varies, the same as`in'the boiler, the said pipe opening directly into tbepipe b. Withinthe latter are placed two disks, c c', both fitting the pipe closely,one above and theother below the mouth ofthe pipe A, said disks being`rigidly attached to a stem, d, which extends through a stungfbox, d',located in the up-` per end of the pipe b, and at its top is jointed to.the

extremityof the shorter arm of` a lever, c, which h as its fulcrum in astandard, f, that springs from a strap, g, which passes across andprojects to either side of the open top of a-verticalpipe, 71 thatisconnected with thefpipe `b by' means ot' horizontal pipes t, which ppeninto the vpipe b one above the upperdisk c and :the other below thelower disk c',

i Withintheupipe his located a safety-valve, 1c, the stem l ofwhichpasses through the strap g, and is jointed at itsl upper end` tothe longer arm ofthe lever e, to the extremity of which theweight m ishung, the said lever being guided in its vibrations by a slottedstandard-n, springing from the strap g, through which standard the levere passes'. l

`It will be' observed that the disks e c' are at one sideof the fulcrumof the` lever e, and the valve 7c at the other side, soth'at when onerises lthe other must Before steam enters the pipe b, the weight m hasraised the disks c c' so far that the upper disk is above itsseat, sayhalf an inch, when the diameter of the pipe A is one and one-quarterinch, leaving an open-4 ing beneath said upper disk, through which steammay ow. Theflower disk c' is never raised to the level of the pipe A,andconsequently no steam ever flows be- 'heath it. l

i Th'eweght m should be placed at a point on the lever where it mayexert on the stem l a pressure nearly equal to that which it is desiredshould always be exerted by steam on the valve k, allowance being madefor thefriction ofthe valve-stems and lever.

The pressureof steam on the valve k is to be kept as nearly as possibleconstant. If five pounds to the square inch be the pressure desired forthe safetyvalve, the weight m should be stationed so as to draw downwardupon the stem l with a force nearly equal to the number of square inchesin the area ofthe valvemultiplied by ive.

The moment the steam from the boiler owing past the upper' disk c exertsupon the safety-valve a pressure greater than that for which it isweighted, the safety-valve rises, the disks c c at the same timedescending and cutting olf the supplyof steam.

When the upper disk arrives at its seat the two `disks togetherconstitute a balanced valve, so that when' the pressure within the pipesT) h i falls below the amount for which the safetyvalve is weighted, thelatter descends, the disksc c' rise, and the disk c again admits steaminto the pipe b. As soon as the pressure upon the safety-valve againexceeds the-prescribed limit, the steam is once more shut off as before,and as soon as the pressure again falls below the prescribed limit,steam is once more admitted as before, and thus the process goes on, tberesult being the keeping of a nearlyconstant quantity of steam in thedriers.

. In fig. 2-is shown a slightly dil'erent arrangement, the pipe h notbeing connected directly with the pipes c', but being connected a't itslower end by a tube, o, with the bottom of a chamber, @into the top ofwhich the upper pipe i opens.

l The pipe o is iilled with mercury, of which there is a quantitysucient to also ll the chamber/r. rlhe oihce of the mercury is simplythat of a packing, to prevent. the escape of any steam past the safety`valve, the operation of the. latter' being the same as in the apparatusshown in iig. 1.

In iig. 3 the safety-valve la is shownas discharging, in addition to theoffice hereinbefore assigned toit, that also of the balanced valve ,cthe latter being in this instance dispensed with, as also is rthe wholesystem 0f pipes i h, the safety-valve being made not only to perform thefunctions of the balanced valve c c', but also to occupy its position inthe pipe b, which in this case is devoid of the stufing-box b', and isopen at the top, except in so far as the strap g covers it.

The valve k forms'the headtof a tube, k, which closely iits the insideof the pipe b, and extends downward therein past the mouth of the pipeA, said tube having on the side next the pipe A an orifice, k2, of thesame diameter as the pipe, and being open at its lower end.

Prior to the admission of steam, the tube k is held down by the weight mso -far in the pipe b that the orifice k2 forms a continuation of thepipe A;' but after steam has entered the pipe b, as soon as it pressesupon the valve k with a force greater than that of the weight lm, thevalve rises, and the tube h1, closing the mouth of the pipe A, shuts offsteam from the pipe b.

As soon as the pressure within the latter falls below that of theweight, the valve descends and admits more steam. r)This apparatus hasthe advantage of being more simple than the latter, and is, perhaps,equally ecient.

I claim as .my invention- A safety-valve, arranged, substantially asdescribed, with reference to the pipe by which steam is conducted from aboiler to the driers of a paper-machine or any other vessel thatcommunicates with the boiler, as to regulate by its movements theadmission of steam to such vessel, allowing only enough to pass tomaintain a constant quantity within the latter.

DANIEL CROSBY.

Witnesses:

E. J. DUDLEY, J oHN CnosBY.

